Rotary printing press



De@ 24 1946. c. s. CRAFTS Erm. '2,413,174

ROTARY PRINTING PRESS 3 Sheets-Sheet l Filed Dec. 2, 1945 E un f :zg AIW Dec. 24, 1946. c. s. CRAFTS ETAL 2,413,174

ROTARY PRINTING PRESS s sheets-sheet 2 Filed Dec. 2, 1945 NNN Dec. 24,1946. c. s. CRAFTS Erm. 2,413,174

ROTARY PRINTING PRESS Filed Dec. 2, 1945 3 Sheets-Sheet 3 1s l, j??? 4Z4 Patented Dec. 24, 1946 ROTARY PRINTING PRESS Curtis S. Crafts andCharles Alonzo Harless, Oak l Park, Ill., assignors to The Goss PrintingPress Company, Chicago, Ill., a corporation of Illinois ApplicationDecember 2, 1943, Serial No. 512,530

19 claims. 1

This invention is an improvement in rotary printing presses, and relatesto the plate cylinder in such a press, being concerned particularly Withmeans for exerting circumferential tension on a stereotype plate carriedby theplate cylinder.

Objects and advantages of the invention will be set forth in parthereinafter and in part will be obvious herefrom, or may be learned bypractice with the invention, the same being realized and attained bymeans of the instrumentalities and combinations pointed out in theappended claims.

The invention consists in the novel parts, constructions, arrangements,combinations, and imvview taken on the line 2-2 of Fig. l;

'Fig.,3 is an enlarged fragmentary sectional if viewtaken on the line3-3 of Fig. 1; i

Fig. 4 is an enlarged fragmentary cross section of the plate cylinder,taken on the line 4-4 of Fig. 1;

Fig. 5 is an end view partly broken away of l* the` plate cylinder ofthis invention;

Fig. 6 is a sectional view oi certain parts of Fig. 5 taken on the line6-6 of Fig. 5; and

Fig. 7 is a view on a smaller scale of the por; tion of Fig. 1, lookingfrom the right of that iigure.

With high speed printing presses, it has been'.

found desirable to hold a` stereotype plate in position on the platecylinders by means exerting circumferential tension on the plate. Withthese high speed presses, there is a tendency for the plate to deform,and eventually crack, due to the continuous and successive pressurewaves exerted on it in the printing operation; thereis some g tendencyfor the plate to become displaced, and there is also the eilect4 ofcentrifugal force. .All of these factors are eliminated or counteractedto a substantial degree by securing the leading edge oi the printingplate to the plate cylinder and by exerting a circumferential resilienttension on the trailing edge of the plate.

The principal object of the present invention is to provide a platecylinder for a rotary printing'press where a resilient circumferentialten 2k sion is exerted onthe trailing edge of the plate while a torsionshaft exerts a, force on the plate against the pull of said resilientmeans.

Another object ofthe invention is to provide a plate cylinder where therespective longitudinal edges of the plate are engaged with hooks, oneset of hooks exerting resilient tension on the trailing edge, and asecond set of hooks controlled by a torsion shaft exert a force on theleading edge against the pull of the resilient hooks.

Another object oi.' the invention is to provide controlling means forthe described torsion shaft which can be turned and locked in positiomtoput the resilient means at the trailing edge of the plate under tension,and to hold the leading edge of the plate in place against the pull ofsuch resilient means.

Another object of the invention is to provide a controlling means fordescribed torsion shaft,

which means is turnable on an axis substantially perpendicular to theaxis of the-plate cylinder, whereby the torsion shaft can be turned andcaused'to putthe tension exerting means at the trailing edge undertension.

It will be understood that the foregoing general description and thefollowing detailed description as well are exemplary and explanatory ofthe invention but are not restrictive thereof.

yReferring now to the drawings, the plate cylinder 2 is provided with alongitudinally extending recessl. The recess 4 ispartially filled by a`plate 6' which is formed with spaced recesses and is secured by bolts8. A cover portion I0 formed integrally therewith has openings I4,opening into the respective recesses in the plate 6.

In each of the described compartments there is mounted a unitaryassembly for exerting spring tension on the trailing edge I6 of thestereotype plate I8. This assembly comprises the plate 6 having pairs ofrecesses 2i. This housing is connected lwith a hook plate 22 by means oftwo pins 24, passing through the recesses 2|. One end of each pin 24 issecured in the housing, while the lower end passes through and looselyengages the hook plate 22, pins 24 vhaving heads 26 somewhat larger thanthe hole through which the pins pass. Mounted in each recess 2| andencircling each pin 24 is a strong compression spring 28 bearing againstthe inside of the recesses y2| and against the hook plate 22. The innerend of the hook plate projects beyond the inner wall 24' of the housing,and is rounded, as shown at 30. With the described construction, hook 22has a limlted pivotal movementby reason of its rounded 3 end 30 and ispressed strongly outwardly by the two springs 28. The hooks 3l of thehook member extend through openings I4 in cover portion i8 and engage inrecesses 32 in the trailing edge of the stereotype plate. This assemblyof tension exerting means may readily be put in'vplacey or removed fromthe plate cylinder as a unit.

The torsion shaft and cooperating mechanism for holding the leading edgeof the plate and for putting the tension exerting means at the trailingedge under tension will now be described. This mechanism comprises a.torsion shaft 38 extending longitudinally of the plate cylinder mountedin bearings 38 in their suitable recesses in the plate cylinder, thebearings being held in place by pins 40 while the outer bearings areheld in place by a cover plate 42 held in place in a suitable recess inthe cylinder by screw bolts 44.

In making the torsion shaft 36, it is machined under torsion, so thatwhen in use and again put under torsion the resulting deflection willresult in accurate positioning of the plate engaging hooks carried bythe shaft. In other words, the hooks 52 on the finished unstressed shaftare positioned along a helix, instead of being strictly in line.-Howeven when the shaft is put under torsion in actual use, the slightsuccessive displacements of the hooks bring the hooks into accurateaxial alignment. f

Further bearings for. the shaft 36 are provided at 46, while the end ofthe shaft terminates in a head 48 and a projecting stud 50, stud 5l)Abeing loumalled in a bracket secured to the end of the plate cylinder.

'I'he shaft 36 is provided with a plurality of outwardly projectinghooks 52 rigidly secured thereto preferably being forged to the shaft,and adapted to engage in recesses 54 in the leading edge 66 of thestereotype plate, these hooks extending through openings 60 in the coverplate 42.

The mechanism for turning and locking the torsion shaft 36 for holdingthe leading edge of the stereotype plate will'now be described. Thismechanism comprises an actuating lever or plate 62 secured to head 48 ofshaft 36 by stud 64. Apertures 66 in actuating plate 62 and the head 48provide journal bearings for the stub shafts 68 projecting from a block10. Block is provided with a transversely extending, eccentricallymounted stub shaft 12. Shafts 68 and 12 are at right angles providinguniversal movement. The ends of shaft 12 are journalled in a stirrup 14integral with arm 16, the other end of which arm is formed into aneccentric strap 18. This eccentric strap 18 engages over a, sphericallycurved bushing 80 being held in place by plate 8|. Bushing 88 is free onthe eccentric head 82, one end 84 of which is fixed to bushing 86journalled in recess 81, bushing 86 having a limited rotary movement byreason of the fixed pin 88 working in slot 90 of the bushing. The outerend 92 of the eccentric head 82 is journalled in a, recess 94 in theplate cylinder` and is provided with the key slot 96 for receiving awrench for turning it. In order to lock the described parts in xedposition a spring pressed plunger 98 adapted to snap into a recess inhead 92 is used.

'l'he operation is as follows: A stereotype plate is put in position onthe cylinder, the hooks 22 for the trailing edge being engaged in theirrecesses 32, while the hooks 52 for the leading edge are engaged inrecesses 54, hooks 52 being -retracted far enough to allow them to slipinto their tion. it is necessary to rotate torsion shaft 36 to 4 causethe hooks 52 to pull the plate against the tension exerted by theresilient hooks at the trailing edge. 'I'his is accomplished by puttinga .wrench in recess 96 and turning the eccentric 82 which, referring tothe lower part of Fig. 5, pushes stirrup 14 to the right, the movementof the eccentric away from the end of the cylinder being compensated forbythe movement about the stub shaft v'12. The movement of 14 to theright moves the actuating plate 62 in a counterclockwise directionvand,since the plate 62 is fixed to shaft 36, the shaft is moved in acounterclockwise direction to cause hooks 62 to exert a circumferentialtension on the plate, which pulls against the tension exerted on theplate by the described resilient means engaging with the trailing edgethereof, and so the plate is put under tension. The

lshaft 36 is locked in this position by the plunger 98 snapping into theappropriate recess in head 92 of the operating eccentric, the eccentricbeing at about dead center in this position.

In removing the plate, the plunger 98 is released and the eccentricturned in the opposite direction, to swing hooks 52 to the positionshown at the right of Fig. 5, in which position the leading edge of theplate can be lifted away from the cylinder about its trailing edge as apivot, to clear the hooks 52, after which hooks 22 are readily released.

Where two stereotype plates are used the described mechanism is induplicate, as shown. The same mechanism may be used for a cylindricalstereotype plate.

'I'he invention in its broader aspects is not limited to the specificmechanisms shown and described but departures may he made therefromwithin the scope of the accompanying claims without departing from theprinciples of the invention and without sacrificing its chiefadvantages.

We 'claimas our invention:

l. In a rotary printing press, a plate cylinder for exertingcircumferential tension on a stereotype plate, comprising resilientmeans for exerting tension on the trailing edge of the plate and means,including a torsion shaft extending longitudinally of the platecylinder, for exerting tension on the leading edge of the plate, againstthe tension of said resilient means.

2. In a rotary printing press, a plate cylinder for exertingcircumferential tension on a stereotype plate, comprising resilientmeans for exerting tension on the trailing edge of the plate, means;including a torsion shaft extending longitudinally of the platecylinder, for exerting tension on the leading eige of the plate, againstthe tension of said resilient means and means for locking said torsionshaft in tension exerting position.

3. In a rotary printing press, a plate cylinder for exertingcircumferential tension on a stereotype plate, comprising resilientmeans for exerting tension on the trailing edge of the plate, means,including a torsion shaft extending longitudinally of the plate forexerting tension on the leading edge vof the plate against the tensionof said resilient means, an actuating member fixed to one end of saidtorsion shaft, and means for oscillating said member in a planesubstantially perpendicular to the axis of the torsion shaft.

4. In a rotary printing press, a plate cylinder for exertingcircumferential tension on a stereotype plate, comprising resilientmeans for exerting tension on the trailing edge of the plate, meansincluding a torsion shaft extending longitudinally of the plate forexerting tension on the leading edge of the plate against the tension ofsaid resilient means, an actuating member xed to one end of said torsionshaft, and turnable means, including an eccentric, for Oscillating saidactuating member in a plane substantially perpendicular to the axis ofthe torsion shaft, for turning said torsion shaft back and forth aboutits axis.

5. In a rotary printing press, a plate cylinder for exertingcircumferential tension on a stereotype plate, comprising resilientmeans for exerting tension on the trailing edge of the plate, means,including a torsion shaft extending longitudinally of the plate forexerting tension on the leading edge of the plate against the tension ofsaid resilient means, an actuating member fixed to one end of saidtorsion shaft, and turnable means, turning on an axis substantiallyperpendicular to the axis of the plate cylinder, for oscillating saidactuating member for turning said torsion shaft back and forth about itsaxis.

6. In a rotary printing press, a plate cylinder for exertingcircumferential tension on a stereotype plate, comprising resilientmeans for exerting tension on the trailing edge of the plate, means,including a torsion shaft extending longitudinally of the plate forexerting tension on the leading edge of the plate against the tension ofsaid resilient means, an actuating member xed to one end of said torsionshaft, means for oscillating said member in a plane substantiallyperpendicular to the axis of the torsion shaft and means for lockingsaid oscillating means in fixed position.

'7. In a rotary printing press, a plate cylinder for exertingcircumferential tension on a stereotype plate, comprising resilientmeans for exerting tension on the trailing edge of the plate, means,including a. torsion shaft extending longitudinally of the plate forexerting tension on the leading edge of the plate against the tension ofsaid resilient means, an actuating member fixed to one endof saidtorsion shaft, turnable means, turning on an axis substantiallyperpendicular to the axis of the plate cylinder, for oscillating saidactuating member for turning said torsion shaft back and forthfabout itsaxis and means for locking said turnable means in a xed position.

8. In a rotary printing press, a plate cylinder for exertingcircumferential tension on a stereo,- type plate, comprising resilientmeans for exerting tension on the trailing edge of the plate, means,including a torsion shaft extending longitudinally of the plate forexerting tension on the leading edge of the plate against the tension ofsaid resilient means, an actuating member xed to one end of said torsionshaft, turnable means, including-a spherically curved eccentric, turningon an axis substantially perpendicular to the axis of the platecylinder, and an eccentric strap, operatively connecting said actuatingmember and said eccentric, whereby the torsion shaft is moved back andforth about its axis.

9. In a rotary printing press, a plate cylinder for exertingcircumferential tension on a stereotype plate, comprising resilientmeans for exerting tension on the trailing edge of the plate, means,including a torsion shaft extending longitudinally of the plate forexerting tension on the leading edge of the plate against the tension ofsaid resilient means, an actuating member fixed to one end of saidtorsion shaft, turnable means, including a spherically curved eccentric,

6 turning on an axis substantially perpendicular to the axisl of theplate cylinder, an eccentric strap, operatively connecting saidactuating member and said eccentric, whereby the torsion shaft is movedback and forth about its axis and means for locking said turnable meansin fixed position.

10. In a rotary printing press, a plate cylinder for exertingcircumferential tension on a stereotype plate, comprising resilientmeans for exerting tension on the trailing edge of the plate, a torsionshaft extending longitudinally of the cyl-- inder, projections carriedby the torsion shaft and engageable with the stereotype plate, andmeians for turning the torsion shaft about its ax s.

l1. In a rotary printing press, a plate cylinder for exertingcircumferential tension on a stereotype plate, comprising resilientmeans for exerting tension on the trailing edge of the plate, a, torsionshaft extending longitudinally of the cylinder, outwardly extendinghooks carried by the torsion shaft and engageable with the back of thestereotype plate and means for turning and locking the torsion shaft.

l2. In a rotary printing press, a plate cylinder for exertingcircumferential tension on a stereotype plate, comprising resilientmeans for exerting tension on the trailing edge of the plate, and means,including a torsion shaft provided with outwardly extending hooks forengaging the leading edge of the plate, said hooks, when the shaft isnot vunder torsion, being progressively displaced from axial alignmentto such an extent that torsional deflection of the shaft with the hooksengaging the plate brings the hooks into substantial laxial alignment.

13. A torsion shaft for exerting a force on the edge of a stereotypeplate, having outwardly extending hooks thereon for engagement with saidplate, said hooks, when the shaft -is not under torsion, beingprogressively displaced from axial alignment to such an extent thattorsional deflection of the shaft with the hooks engaging the platebrings the hooks into substantial axial alignment.

14. A torsion shaft -for exerting a force on the edge of a stereotypeplate, having outwardly extending hooks thereon for engagement with saidplate, said hooks, when the shaft is not under torsion, being arrangedalong a helix, the deection of the shaft by torsion serving to bring thehooks into substantial axial alignment.

15. In a rotary printing press, a plate cylinder for exertingcircumferential tension on a curved stereotype plate, said cylinderhaving a recess in its surface to receive a removable plate hookassembly in substantial alignment axially of the cylinder surface, saidhook assembly comprising a plate having spaced recesses extending normalto the length of the plate, a plurality of hooks pivotally mounted withrespect to the recessed plate, compression springs in the recessesurging the hooks away from the recessed plate, and means for retainingthe assembly in cylinder recess.

16. In a rotary printing press, a plate cylinder for exertingcircumferential tension on a curved stereotype plate, said cylinderhaving a recess in its surface to receive a removable plate hookassembly in substantial alignment axially of the cylinder surface, saidhook assembly comprising a plate having spaced recesses extending normalto the length of the plate, a plurality of hooks pivotally mounted withrespect to the recessed plate, compression springs in the recessesurging the hooks away from the recessed plate, pins,

mounted in the plate recesses and encircled by said springs, said pinsextending through said hooks and serving to retain them assembled to theplate, and means for retaining the assembly in cylinder recess.

17. In a rotary printing press, the combination of a plate cylinder forsupporting a printing plate, resilient means carried by said cylinderfor exerting tension on one edge of the plate, and movable means carriedby said cylinder torsionally operated to exert aV predeterminedtorsional load on the other edge of the plate against the resiliency ofsaid resilient means.

i8. In a rotary printing press, the combination of a plate cylinder forsupporting a printing plate, resilient means acting on one straight edgeof the plate to exert resilient tension thereon, movable means includinga torsional shaft extending longitudinally of the cylinder for exertinga pull on the other straight edge of the plate against the resiliency ofsaid resilient means. and operating means for stressing said shaft witha predetermined torsional force as said movable means engage with thesaid other edge of the plate.

19. In a rotary printing press the combination of a plate cylinder forsupporting a printing plate, means 'for securing a parti-cylindricalprinting plate thereto including a shaft carrying plate engaging hookswhich project through the surface of the cylinder to engage in recessesin the concave side of the plate near an edge thereof and means forangularly moving said shaft and hooks including an arm connectedthereto, an eccentric and a link connecting the eccentric and arm.

CURTIS S. CRAFTS. CHARLES ALONZO HARLESS.

